Update themes-colors.md

Removed the principles section as this section has been added as the part of the new article "Site theme" under brand center.

Author: maggierui

docs/design/themes-colors.md

@@ -33,22 +33,6 @@ SharePoint includes a palette that supports dark themes. The SharePoint-provided
 
 ![SharePoint dark theme color palette, Red EF6950, Yellow FFC83D, Green 00b294, Blue 3a96dd, Purple 9c89e9, Grey b1adab](../images/sharepoint-themes-dark.png)
 
-## Principles
-
-The following design principles helped form the current SharePoint themes and color palette.
-
-### Guided
-Our theming system works at a global level so that updates can be made consistently across each site, allowing users to optimize their websites effortlessly. Our theming system operates in a controlled environment so that successful outcomes can be optimized quickly.
-
-### Smart and efficient
-Our theming system expedites the site creation process by using smart algorithms to generate options that maximize aesthetic choices.
-
-### Professional
-Our themes embody a professional look and feel that ensures coherency and conveys the brand of our enterprise audiences.
-
-### Accessible
-Our built-in accessibility checker ensures universal design at all levels of default themes. For users who decide to customize, we provide helpful guidelines to design for accessibility.
-
 ## See also
 
 - [Accessibility](accessibility.md)